局所進行がン治療における陽子線治療の適応選択に関する研究

质子束放射治疗局部晚期和深层肿瘤的潜在适用性研究在质子束放射治疗中，改善了辐射的剂量分布，使肿瘤获得较高剂量的照射，而对正常组织给予较小剂量的照射，这一特点提供了相对于光子的明确的治疗优势。本研究评估了其他治疗方法的价值，包括快中子治疗、近距离放射治疗、术中放射治疗、适形放射治疗、不同分割放射治疗以及放疗联合热疗或化疗。结合评价结果，对质子治疗的临床应用实例进行了研究，剂量-体积直方图分析显示了质子治疗相对于常规放射治疗的优越性。加速短程辐射、场中场方法和不均匀分割辐射在质子治疗中也具有重要的价值。在筑波大学的一项临床质子疗法中，已经治疗了各种深层次器官的肿瘤，在头颈部、肺、食道、肝脏、子宫颈、膀胱和前列腺癌的治疗上取得了令人印象深刻的临床成功。与其他放射治疗方法相比，质子放射治疗在以下方面有价值：(1)IIIb期宫颈癌、局部晚期肺癌、食道癌以及术后复发或无法手术的胆管癌的根治性治疗；(2)直肠癌的术前放射治疗；(3)质子与化疗的联合治疗。

Investigation on potential applicability of proton beam radiotherapy for treatment of locally advanced and deep-seated tumors.In proton beam radiotherapy improved dose distribution of radiation is accomplished so that a higher dose can be administered to the tumor while a lesser dose is given to the normal tissue, and such characteristic provides definite treatment advantage over photons. In this study the value of other treatment modalities were evaluated including fast neutron therapy, brachytherapy, intraoperative radiotherapy, conformation irradiation, variously fractionated radiation, and radiotherapy combined with hyperthermia or chemotherapy. By taking into account for the results of such evaluations, clinical examples which could be successfully treated with protons were finally investigated.The dose-volume histogram analysis has demonstrated the superiority of proton beams over conventional radiations. It was also demonstrated that accelerated short-term radiation, 'field in field' method, and unevenly fractionated radiation were of great value in proton therapy. In a clinical proton therapy at University of Tsukuba, tumors of various deep-seated organs have been treated, and impressive clinical success has been achieved in treatment of tumors of the head and neck, lung, esophagus, liver, uterine cervix, bladder and prostate. In contrast to other radiotherapeutic modalities, proton beam radiotherapy is considered to be valuable in : (1) radical treatment of stage IIIb uterine cervix ca, locally advanced lung ca, esophagus ca, and post-operative recurrent or inoperable ca of the biliary tract, (2) pre-operative radiotherapy of rectal ca, and (3) combined treatment of protons and chemotherapy.The above accomplishment obtained in this study has stimulated us to design a dedicated proton therapy facility.